The present invention relates to a system for providing an electrical connection. More specifically, it relates to a system for providing an electrical connection between a cable and an electrically conductive track. Such a system may advantageously be used in order to provide power and data to an electronic shelving display system.

BACKGROUND OF THE INVENTION

The necessity of providing accurate product information, in particular pricing information, to customers in a retail environment makes shelving systems and shelf edge labels an integral part of any retail store. In order to reduce the costs of manually updating shelf edge labels and improve the accuracy of displayed product information, there is a growing desire to provide shelving systems incorporating electronic devices, particularly networked electronic devices such as electronic shelf label displays.

Such networked devices require a supply of power, which may be provided either by batteries, or by hard-wired power lines which are typically connected to the device through the shelving. Battery powered devices provide a superior degree of flexibility, as the device may be located anywhere throughout a store or warehouse without the issue of having to provide a power supply. The lifetime of the battery is, however, a limiting feature, as the necessary replacement of batteries on a regular basis is both time-consuming and costly. Hard-wired power supplies do not have a finite lifetime, but are more expensive to install, and can limit the positions at which a shelf edge device may be located to those positions with an available power outlet.

Similarly, data must be provided to the networked devices in order for each device to update the displayed information when required. Data may be provided wirelessly or through hard-wiring. Wireless formats allow flexibility in the positioning of networked devices, but potentially leave the system open to hacking or signal jamming. Hard-wired data supply is more secure, but as with hard-wired power, it is costly to install and can restrict the positioning of networked devices.

Power and/or data may advantageously be provided to a shelving system by an electrically conductive track incorporated into the shelving system. This ensures that the electrical connection to the shelf label displays does not interfere with products on the shelves and is not damaged or otherwise affected by movement of the products on the shelves. However, such a track must somehow be connected to a power and/or data supply. This connection typically takes the form of a flexible cable.

It is important that any electrical connector that connects the power supply to the electrically conductive track should be safe and simple to use, so that it may be installed or maintained by unskilled workers in a retail environment. The connector should be simple to connect and remove, in order to allow for quick and easy reconfiguration of shelving. Such a connector should also be compact, so as not to interfere with the products displayed on a shelving system, and robust enough to survive incorrect handling by users. In order to provide power to the large number of displays that may be required for a set of shelves, it is necessary to provide a relatively high current to the electrically conductive track, typically of the order of 5 Amperes. This high current means that resistive losses in connectors can be significant. It is important that any connector provides a good electrical connection with minimal resistive losses. In these circumstances, typically a terminal block is used. A terminal block for coupling a cable to a track would comprise one clamping screw to connect the cable to the terminal block and another clamping screw to connected the terminal block to the track. However, when connecting power and data to a track this requires a user to screw eight screws in order to make the connections and to unscrew eight screws to disconnect the cables from the track. Shelving units in retail stores are reconfigured frequently and so it is desirable to be able to provide for electrical connection and disconnection more simply.

It is an object of the present invention to provide an electrical connector and a system for power and/or data provision to an electrically conductive track that is safe, easy to use, and meets the above described requirements. It is a further object of the invention to provide a safe and secure supply of power and/or data to an electronic shelving display system such that a high volume of data may be transmitted to a plurality of networked displays.

SUMMARY OF THE INVENTION

In a first aspect, there is provided an electrical connector for connecting a cable to an electrically conductive track comprising: a screw, having a proximal end and a distal end; and a connector body, having an aperture through which the screw passes, and a resilient contact portion configured to abut the distal end of the screw; wherein the screw is movable to urge the resilient contact portion in a distal direction against the track, and the cable is retainable between the proximal end of the screw and the connector body.

This arrangement has the advantage that only a single screw is required to connect and disconnect the cable from the track.

Ordinarily, a particular difficulty with using a single screw both to clamp a cable and to contact a track is that tolerances have to be very tight. The head of the screw must clamp the cable to ensure a good electrical connection at the same point that the end of the screw makes contact with the track. If the screw is too long relative to a surrounding housing then either the cable will not be clamped sufficiently or the track will be damaged. If the screw is too short relative to the surrounding housing then electrical contact will not be made with the track. However, in this aspect of the invention, the resilient contact portion allows for a good connection to be made with both the track and the cable without requiring tight tolerances on the dimensions of the components. The resilient contact portion provides a good electrical contact with the track while allowing the screw to deform it to a greater or lesser extent. Advantageously, the electrical connector comprises an electrically insulating housing configured to retain, in use, a portion of the electrically conductive track. The housing is preferably configured to retain the connector body so that, in use, the resilient contact portion contacts the electrically conductive track.

The housing may comprise a screw thread engageable with the screw, and configured so that movement of the screw along the screw thread in a distal direction urges the resilient contact portion against the track.

The housing may comprise gripping means configured to grip the electrically conductive track or an element to which the track is fixed, so as to allow relative movement between the electrically conductive track and the housing in a first direction, and prevent relative movement in a second direction opposite the first direction. The gripping means may advantageously allow the electrically conductive track to be inserted into the housing in the first direction, but prevent the track from moving back out of the housing accidentally, for example due to creep of the track or connector, or under gravity. The gripping means may advantageously grip only a base portion, or an insulating substrate portion, of the electrically conductive track, so that a powerful movement of either the track or the housing may overcome the gripping force of the gripping means. This may advantageously allow the track to be pulled free from the housing without damaging the electrically conductive portion of the track.

In a preferred embodiment, the gripping means may be formed from a series of teeth protruding from the housing, which may advantageously act as a ratchet. The teeth are preferably arranged so that the tips of the teeth point in the first direction, so that the track can move in the first direction without catching on the teeth. Movement of the track in the second direction, however, causes the teeth to embed in the track, gripping the track and preventing movement in the second direction. Preferably the size of the teeth is such that they embed in and grip only a base portion, or an insulating substrate portion, of the electrically conductive track.

Advantageously, the resilient contact portion provides an electrical connection to the track, in use, with the screw in a first position. The screw may be movable in a distal direction to a plurality of second positions, wherein the resilient contact portion provides an electrical contact to the track in each of the plurality of second positions. So the user does not need to be very concerned about how far to screw the screw in the distal direction once the cable is clamped.

In one embodiment, the resilient contact portion comprises a ridge connected to a base, configured so that, in use, the distal end of the screw abuts the ridge and the base abuts the electrically conductive track, such that movement of the screw in a distal direction compresses the ridge and urges the base against the track. However, other shapes for the resilient contact portion are possible that provide for resilient deformation on application of a force in a distal direction, including a concertina shape, a spiral shape and an S shape.

An electrically conductive cable lug may be retainable between the proximal end of the screw and the connector body.

Advantageously, the electrical connector is configured so that a plurality of connector bodies are retained within the housing so as to connect, in use, to the electrically conductive track in a plurality of positions. The housing is configured to retain an electrically conductive track comprising a plurality of ribbon conductors, and a plurality of connector bodies, wherein each connector body is configured to connect to a corresponding ribbon conductor. In a second aspect of the invention, there is provided a system comprising: an electrically conductive track; a cable; and an electrical connector comprising a screw, having a proximal end and a distal end, and a connector body, having an aperture through which the screw passes and a resilient contact portion configured to abut the distal end of the screw; wherein the cable is retainable between the proximal end of the screw and the connector body, and the screw is movable to urge the resilient contact member against the track.

Preferably, the connector comprises an electrically insulating housing configured to retain a portion of the electrically conductive track. The housing may retain a portion of the cable. The housing is advantageously configured to retain the connector body so that the resilient contact portion contacts the electrically conductive track.

The housing may comprise a screw thread engageable with the screw, configured so that movement of the screw along the screw thread in a distal direction urges the resilient contact portion against the track.

Preferably the housing comprises a gripping means as decribed in relation to the first aspect of the invention.

The resilient contact portion may provide an electrical connection to the track with the screw in a first position, and the screw may be movable in a distal direction to a plurality of second positions, wherein the resilient contact portion provides an electrical contact to the track in each of the plurality of second positions. The cable may advantageously be coupled to an electrically conductive cable lug which is coupled to the screw so as to provide an electrical connection between the cable and the screw.

The resilient contact portion may comprise a ridge connected to a base, configured so that the distal end of the screw abuts the ridge and the base abuts the electrically conductive track, such that movement of the screw in a distal direction resiliently compresses the ridge and urges the base against the track. However, other shapes for the resilient contact portion are possible that provide for resilient deformation on application of a force in a distal direction, including a concertina shape, a spiral shape and an S shape. Advantageously, the electrically conductive track comprises a plurality of electrically conductive elements, and the housing retains a plurality of electrical connectors so that each connector contacts a corresponding electrically conductive element.

The system may comprise a plurality of cables retained within the housing, such that each cable is coupled to a connector that contacts a corresponding electrically conductive element.

In a third aspect, there is provided an electronic shelving display system comprising: at least one shelf support; at least one electrically conductive track, mountable to the shelf support; at least one cable; and at least one electrical connector; wherein the connector comprises a screw, having a proximal end and a distal end, and a connector body, having an aperture through which the screw passes and a resilient contact portion configured to abut the distal end of the screw; wherein the cable is retained between the proximal end of the screw and the connector body, and the screw is movable to urge the resilient contact member against the track, in order to provide an electrical connection from the cable to the track to allow for the supply of power and/or data to the shelf. An electronic shelving display system preferably comprises an electrically insulating housing, retaining a portion of the electrically conductive track and a portion of the cable. The housing may be mounted to the shelf support.

Preferably the housing comprises a gripping means as decribed in relation to the first aspect of the invention.

The electrically conductive track may comprise a plurality of electrically conductive elements, and the housing may be configured to retain a plurality of electrical connectors so that, in use, each connector is configured to contact a corresponding electrically conductive element. The electronic shelving display system may comprise a plurality of cables retained within the housing, such that each cable is coupled to a connector configured to contact a corresponding electrically conductive element.

Each cable may carry power and/or data, such that power and/or data is transmitted through each connector to the corresponding electrically conductive element of the electrically conductive track. An electronic shelving display system may additionally comprise at least one electronic shelf label display, coupled to the electrically conductive track in order to allow for the supply of power and/or data to the electronic shelf label display.

It should be clear that features of the invention described in relation to one aspect of the invention may equally be applied to other aspects of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a connector body in accordance with an embodiment of the invention;

Figure 2 is a side view of the connector body of Figure 1 ;

Figure 3 is an underside view of the connector body of Figure 1 ; Figure 4 is an exploded view of a connector system in accordance with an embodiment of the invention;

Figure 5 is an assembled view of the connector of Figure 4;

Figure 6 is a plan view of the connector of Figure 4; Figure 7 is a cross section of the connector of Figure 4, with the screw in an unconnected position;

Figure 8a is a cross section of the connector of Figure 4, with the screw in a connected position;

Figure 8b is a detail view of the connector body in Figure 8a; Figure 9a is a schematic illustration of a shelving system including a connector system as illustrated in Figured 4 to 8b; and

Figure 9b is a detail view of the connector of Figure 9a;

Figure 10 is a is a plan view cross section of the connector system of Figure 4.

DETAILED DESCRIPTION Figure 1 is a perspective view of a connector body 10 for use in a connector as illustrated in Figure 4. Figure 2 is a side view of the connector body of Figure 1. Figure 3 is an underside view of the connector body of Figure 1.

The connector body 10 is formed from a single sheet of phosphor bronze PB102, with a tin over nickel finish. The connector body 10 comprises a resilient contact portion 12, connected to an upper portion 18 by a connecting beam 11. The upper portion 18 has an aperture 19 formed in it and is dimensioned to allow the shaft of a screw to pass through it. The resilient contact portion 12 comprises base portions 16 and a ridge portion 14 between the base portions. The ridge portion 14 projects from the base portions 16 towards the upper portion 18. The connector body is formed from a sheet of phosphor bronze of around 0.2mm thick so that the ridge portion is readily compressible, as will be described. In an uncompressed state the ridge portion extends from the base portion 16 towards the upper portion by a distance of around 1 mm. As will be described with reference to figures 7 and 8, a screw can passed through the aperture 19 from an opposite side of the aperture to the ridge 14 and moved in a direction towards the apex 15 of the ridge, herein referred to as the distal direction. Further movement of the screw in the distal direction will cause a distal end of the screw to contact the apex 15. If an underside of the base portions 16 is abutting a conductive track, as will be described, further distal movement of the screw will compress the ridge and thereby spread the base portions 16 apart from one another.

Figure 4 is an exploded view of a connector system that incorporates a connector body as shown in Figures 1 to 3. The connector connects an electrically conductive track 30 to a plurality of cables 40. The connector comprises a base housing 20 and a cover 22, both formed formed from an insulative plastics material. In this example the cover 22 is formed from acrylonitrile butadiene styrene (ABS) and the base housing is formed from polyamide. Engaging lips on the base housing engage the sides of the track 30 in a manner that allows the base housing 20 to slide along the length of the track. The base housing 20 comprises four bores 26 configured to receive respective electrically conductive screws 24 .Below each of the bores 26, but not visible in Figure 4, a connector body 10 and a threaded insert

23 are received, as will be described with reference to Figure 7 and 8.

There are four cables 40 shown in Figure 4, corresponding to the four bores 26. External to the connector, the cables 40 are received in a cable jacket 41. Inside the connector the four cables are each terminated by a cable lug 42 which overlies one of the bores 26. A screw

24 passes through each cable lug and into the respective bore 26, as can be seen clearly in Figure 7, which is a cross sectional view of an assembled connector. Cover apertures 26 are provided in the cover 22 to permit access to each of the screws 24. There are also four electrically conductive strips 32 on the conductive track 30. Each cable 40 is connected to a different electrically conductive strip 32 by the connector system. In this example two of the cables carry power and two of the cables carry data.

Figure 5 is a perspective view of an assembled connector of the type shown in Figure 4, and Figure 6 is a plan view of Figure 5. The cover can be seen engaged to the base housing, and the screws 24 are clearly accessible through cover apertures 26 to allow for loosening and tightening of the screws 24.

Figure 7 is a cross sectional view of the connector of Figures 5 and 6. The electrical track 30 is shown and comprises an insulating substrate 34 and electrically conductive strips 32. A screw 24 is shown passing through a cable lug 42, a bore 26, the aperture 19 in a connector body 10 and a threaded insert 23. The screw 24 is formed from an electrically conductive material such as phosphor brass. A thread on the screw 24 engages a thread on threaded insert 23. The screw is shown in a position in which it is not engaged with the ridge 14 of the connector body so that no electrical connection is made between the cable lug 42 and the electrically conductive strip 32. The cover 22 is engages with the base housing by a mechanical interlock between base lugs 28 on the base and cover lugs 29 on the cover.

Figure 8a is a cross sectional view of the assembly of Figure 7 but with the screw 24 moved distally to provide an electrical connection between the cable lug 42 and the electrically conductive strip 32. Figure 8b is a detail view of the connector body in this position. It can be seen that in the position shown in Figures 8a and 8b the cable lug 42 is clamped between a screw head at the proximal end of the screw and the base housing 20. The distal end of the screw is in contact with the resilient contact portion of the connector body and has compressed the ridge 14, urging the base portion 16 into contact with the electrically conductive strip 32. In this way an electrical connection is made between the cables 40 and the track 30.

The advantage of this arrangement is that the screw can be screwed into the threaded insert to clamp the cable lug 42 and simultaneously contact the connector body 10 and because of the ability of the resilient contact portion 12 of the connector body to deform, the relative dimensions of the base housing 20, the cable lugs 42 and screws 24 do not have to be controlled within very tight tolerances. Furthermore, the ability of the resilient contact portion 12 of the connector body to deform reduces the chances that the screw could damage the track 30 by being over tightened and reduces the chance of damage to the track if the track and connector are pulled apart by a user before the screws 24 are loosened. The resilient contact portion can simply slide along the track with tearing the surface of the track.

Figure 9a is a schematic illustration of a shelving system 50 including a connector as described with reference to Figures 1 to 8b. The shelving system 50 comprises a shelf 52 supported by a shelf support 54. Displays 56 are connected to a front edge of the shelf 52. Power and data is provided to the displays 56 through electrically conductive tracks 30, 35 and 37. Preferably electrical power is provided at a voltage of 15V and a current of 5A in a direct current (DC) configuration, and data in an appropriate data format, such as 4xRS485 data format, for electronic shelf label displays. Alternatively, the power and data supply 66 may supply electrical power at a voltage of 12V, or 24V, according to the requirements of the system.

Only a single shelf is shown in Figure 9a but the system may include several shelves supported by a single shelf support and may include several shelf supports. Each shelf may have several displays 56. A connector is positioned at the base of the shelf support 54 and the connector cover 22 can be seen. The connector connects power and data cables in the cable jacket 41 to the track 30, as is more clearly shown in the detail view of Figure 9b. The connector can slide on or snap on to the track 30. In Figures 9a and 9b, the track 30 is shown covered by a track cover 38. The tracks 30, 25 and 37 are fixed to the shelf support and shelf and do not interfere with products on the shelf.

Figure 10 is a plan view cross section of the connector system of Figures 4 to 8, showing only the track 30 and base housing 200. The base housing 200 comprises opposing sets of teeth 250 arranged to engage and grip the sides of the track 30. The teeth 250 are arranged so that the tips of the teeth are angled towards a first end 260 of the base housing. This allows the track to be inserted into the base housing 200 by sliding it into the base housing until the track reaches the first end of the housing. The teeth 250 then act to stop the track moving away from the first end of the base housing, by embedding in and gripping the sides of the track 30.

A connector as described allows for simple and reliable connection of cable to a conductive track system, using a minimal number of screws and that is not easily damaged by misuse.